The intelligence of the person may affect how he or she will respond to communications, but it usually is not a major factor. If the communication uses facts and logical reasoning to prove its point, the person will be more willing to accept it and be persuaded than if it has no factual base and the statements are illogical. However, most television commercials and other communications do not appeal to a person's logic, but rather to other motivations.
The credibility of the speaker is also a variable in determining the effect of a communication. The higher the credibility, the greater the impact. However, even if the speaker has low credibility, over time, the ideas separate themselves from the speaker in the mind of the person that witnessed the communication. Therefore, the ideas may have more of an affect than it would seem at first.
If a communication is dissonant with a person's attitude, he or she may try to avoid situations in which exposure to that communication may occur. However, if the person does end up being exposed to a strong communication, then chances are it will persuade him or her more easily than if an immunity had been built up by being exposed to weaker arguments before this exposure (Secord and Backman, 194).
Perhaps most important is how strongly a person believes in his or her own ideas. If a person does not have a strong attitude toward something, it is likely that it will be quite easy to change his or her opinion. However, if a person already has strong convictions, a communication that tries to change his or her mind will have little effect. Debates between two ideas only seem to strengthen a person's current beliefs.